Washington Sexual Fulfillment in Chopin's Awakening The controversial Decisions of the us government in History Claudiuss Decision to Invade Britain in AD43 as Motivated by a desire to Emulate julius caesar Critical Assessment of 3 causes of World War 1 Treatment of Shylock by the. Roosevelt's New deal and Unemployment The various Forms of the cosmological Argument for the Existence of God Shakespeare bible strunk anatomy nonfiction"tions reference fiction poetry m top 150 subjects titles authors world Lit. This article is about a type of emotional attachment. For the modern popular-fiction genre, see romance novel. For the historical era associated with the arts, see. For other uses, see, romance (disambiguation). Romance is a pleasurable emotional feeling of love for another person, and as well refers to a collection of courtship behaviors undertaken to express the emotions created by the feeling. The feeling of romantic love is associated with sexual attraction, but romantic feelings can exist without expectation of physical consummation and be subsequently expressed.
Love, at, first, sight, contest Rules nbc
Adventures of cio structural Transformation Through e-business Essay example marketing Strategy Essay co sleeping Advance medical Tech. Case Study United 93 review evidence based Nursing Essay rabbits Hawaiian Memories, Inc. Apple Essay the food and Drug Administration Essay vocation Nature of Thought Paper Social Problems Associated with Street Gangs Essay case with Coleen Colombo and Colleagues Resisting Mortgage Essay ihop Mondavi case sickle cell Anemia comprehensive cafr Analysis - ventura county What Is Human Services? Essay about quality Associates Case Information Systems Risk management Financial Analysis - yum! Brands and Darden Restaurant Continental Carriers Inc. Case Analysis Essay the nigerian Constitution in report 1960 Essay the boogeyman International Paper Essay on Regulatory Agency Effects of Technology on the Accounting Profession Steamboat Case Essay example history of the Bra Essay on riordan heart failure Essay airbus boeing m - free term Papers. Aboriginal Children and Women are an Impediment to development in Canada Prosthetic 3D Printers The negative effects of Steroid Use What is Web Hosting? Creating Capabilities: The human development Approach by martha nussbaum The Impact of Climate Change on Australian fauna legalization of Marjuana boston beer Case Study new Belgium Brewing Case Study on Educational toy compare the financial situations of two companies. Corona beer: from a local Mexican Player to a global Brand Fast food feast - mcdonald's Versus Whataburger Global Human Capital Management Trends Grenadier Marketing Case Analysis Human Resources wh smith Instructor Manual Marketing Plan for New Drink McDonald's Corporation Analysis Medical Practices of the. Community qualitative research Report Adoption. Foster Parenting African Americans and the Prison System.
866, 867 which about the middle of the third month come together and unite in front of the cornea. They remain united until about the end of the sixth month. 11 The lacrimal sac and nasolacrimal duct result from a thickening of the ectoderm in the groove, nasoöptic furrow, between the lateral nasal and maxillary processes. This thickening forms a solid cord of cells which sinks into the mesoderm; during the third month the central cells of the cord break down, and a lumen, the nasolacrimal duct, is established. The lacrimal ducts arise as buds from the upper part of the cord of cells and secondarily establish openings ( puncta lacrimalia ) on the margins of the lids. The epithelium of the cornea and conjunctiva, and that which lines the ducts and alveoli of the lacrimal gland, are of ectodermal origin, diary as are also the eyelashes and the lining cells of the glands which open on the lid-margins. 12 contents bibliographic record illustrations subject index check out our other writing samples, like our resources on Essay about Aristotle, essay about Racism, feminism Essay. see more popular essays health and Safety culture Essay is Canada a nation?
(Kollmann.) ( see enlarged image ). 868 Section of developing eye of trout. (Szily.) ( see enlarged image ) The anterior chamber of the eye appears as a cleft in the mesoderm separating the lens from the overlying ectoderm. The layer of mesoderm in front of the cleft forms the substantia propria of the cornea, that behind the cleft the stroma of the iris and the pupillary membrane. The fibers of the ciliary muscle are derived from the mesoderm, but those of the Sphincter and Dilatator pupillæ are of ectodermal origin, being developed from the cells of the pupillary part of the optic cup. 9 The sclera and choroid are derived from the mesoderm surrounding the optic cup. 10 The eyelids are formed as small cutaneous folds ( Figs.
Love, at, first, site
By the report second month the lens is invested by a vascular mesodermal capsule, the capsula vasculosa lentis; the bloodvessels supplying the posterior part of this capsule are derived from the hyaloid artery; those for the anterior part from the anterior ciliary arteries; the portion. By the sixth month all the vessels of the capsule are atrophied except the hyaloid artery, which disappears during the ninth month; the position of this artery is indicated in the the adult by the hyaloid canal, which reaches from the optic disk to the posterior. With the loss of its bloodvessels the capsula vasculosa lentis disappears, but sometimes the pupillary membrane persists at birth, giving rise to the condition termed congenital atresia of the pupil. 866 Horizontal section through the eye of an eighteen days embryo rabbit. (Kölliker.) ( see enlarged image ) The vitreous body is developed between the lens and the optic cup.
The lens rudiment and the optic vesicle are at first in contact with each other, but after the closure of the lens vesicle and the formation of the optic cup the former withdraws itself from the retinal layer of the cup; the two, however, remain. This network, derived partly from the cells of the lens and partly from those of the retinal layer of the cup, constitutes the primitive vitreous body ( Figs. At first these protoplasmic processes spring from the whole of the retinal layer of the cup, but later are limited to the ciliary region, where by a process of condensation they appear to form the zonula ciliaris. The mesoderm which enters the cup through the choroidal fissure and around the equator of the lens becomes intimately united with this reticular tissue, and contributes to form the vitreous body, which is therefore derived partly from the ectoderm and partly from the mesoderm. 867 Sagittal section of eye of human embryo of six weeks.
4 The cells of the inner or retinal layer of the optic cup become differentiated into spongioblasts and germinal cells, and the latter by their subdivisions give rise to neuroblasts. From the spongioblasts the sustentacular fibers of Müller, the outer and inner limiting membranes, together with the groundwork of the molecular layers of the retina are formed. The neuroblasts become arranged to form the ganglionic and nuclear layers. The layer of rods and cones is first developed in the central part of the optic cup, and from there gradually extends toward the cup margin. All the layers of the retina are completed by the eighth month of fetal life.
5 The optic stalk is converted into the optic nerve by the obliteration of its cavity and the growth of nerve fibers into. Most of these fibers are centripetal, and grow backward into the optic stalk from the nerve cells of the retina, but a few extend in the opposite direction and are derived from nerve cells in the brain. The fibers of the optic nerve receive their medullary sheaths about the tenth week after birth. The optic chiasma is formed by the meeting and partial decussation of the fibers of the two optic nerves. Behind the chiasma the fibers grow backward as the optic tracts to the thalami and mid-brain. 6 The crystalline lens is developed from the lens vesicle, which recedes within the margin of the cup, and becomes separated from the overlying ectoderm by mesoderm. The cells forming the posterior wall of the vesicle lengthen and are converted into the lens fibers, which grow forward and fill up the cavity of the vesicle (Fig. The cells forming the anterior wall retain their cellular character, and form the epithelium on the anterior surface of the adult lens.
Sight, size drawing Method
Through the groove and fissure the mesoderm extends into the optic stalk and cup, and in this mesoderm a bloodvessel is developed; during apple the seventh week the groove and fissure are closed and the vessel forms the central artery of the retina. Sometimes the choroidal fissure persists, and when this occurs the choroid and iris in the region of the fissure remain undeveloped, giving rise to the condition known as coloboma of the choroid or iris. 865 Optic cup and choroidal fissure seen from below, from a human embryo of about four weeks. (Kollmann.) ( see enlarged image ) The retina is developed from the optic cup. The outer stratum of the cup persists as a single layer of cells which assume a columnar shape, acquire pigment, and form the pigmented layer of the retina; the pigment first appears in the cells near the edge of the cup. The cells of the inner stratum proliferate and form a layer of considerable thickness from which the nervous elements and the sustentacular fibers of the retina, together with a portion of the vitreous body, are developed. In that portion of the cup which overlaps the lens the inner stratum is not differentiated into nervous elements, but forms a layer of columnar cells which is applied to the pigmented layer, and these two strata form the pars ciliaris and pars iridica retinæ.
See enlarged image development. The eyes begin to develop as a pair of diverticula from the lateral aspects of the forebrain. These diverticula make their appearance before the closure of the anterior end of the neural tube; after the closure of the tube they are known as the optic vesicles. They project toward the sides of the head, and the peripheral part of each expands to form a hollow bulb, while the proximal part remains narrow and constitutes the optic stalk ( Figs. The ectoderm overlying the bulb becomes thickened, invaginated, and finally severed from the ectodermal covering of the head as a vesicle of cells, the lens vesicle, which constitutes the rudiment of the crystalline lens. The outer wall of the bulb becomes thickened and invaginated, and the bulb is thus converted into a cup, the optic cup, consisting of two strata of cells (Fig. These two strata are continuous with each other at the cup margin, which ultimately overlaps the front of the lens and reaches as far forward as the future aperture of the pupil. The invagination is not limited to the outer wall of the bulb, but involves also its postero-inferior surface and extends in the form of a groove for some distance along the optic stalk, sons so that, for a time, a gap or fissure, the choroidal fissure.
the bulb, and that of posterior pole to the central point of its posterior curvature; a line joining the two poles forms the optic axis. The axes of the two bulbs are nearly parallel, and therefore do not correspond to the axes of the orbits, which are directed forward and lateralward. The optic nerves follow the direction of the axes of the orbits, and are therefore not parallel; each enters its eyeball. To the nasal side and a little below the level of the posterior pole. The bulb measures rather more in its transverse and antero-posterior diameters than in its vertical diameter, the former amounting to about., the latter to about.5.; in the female all three diameters are rather less than in the male; its antero-posterior diameter. 863, transverse section of head of chick embryo of forty-eight hours incubation. See enlarged image. 864, transverse section of head of chick embryo of fifty-two hours incubation.
Contents, bibliographic record, illustrations, subject index, henry Gray (18211865). Anatomy of the human Body. The Organ of Sight (Organon Visus; The eye). The bulb of the eye ( bulbus oculi; eyeball or organ of sight, is contained database in the cavity of the orbit, where it is protected from injury and moved by the ocular muscles. Associated with it are certain accessory structures, viz., the muscles, fasciæ, eyebrows, eyelids, conjunctiva, and lacrimal apparatus. 1, the bulb of the eye is imbedded in the fat of the orbit, but is separated from it by a thin membranous sac, the fascia bulbi (page 1024). It is composed of segments of two spheres of different sizes. The anterior segment is one of a small sphere; it is transparent, and forms about one-sixth of the bulb.
Reflections on Union Station: an essay by Stephen
Select searchWorld Factbookroget's Int'l ThesaurusBartlett's"tionsRespectfully"dFowler's King's EnglishStrunk's StyleMencken's LanguageCambridge historyThe king James BibleOxford ShakespeareGray's AnatomyFarmer's cookbookpost's EtiquetteBrewer's Phrase fableBulfinch's MythologyFrazer's Golden summary boughAll VerseAnthologiesDickinson,. Hopkins, ats, wrence, sters, ndburg, ssoon,. Wordsworth, ats, l NonfictionHarvard ClassicsAmerican EssaysEinstein's RelativityGrant, osevelt,. Wells's HistoryPresidential InauguralsAll FictionShelf of FictionGhost StoriesShort StoriesShaw, ein, evenson,. Reference anatomy of the human Body. The Organs of the senses and the common Integument. The Organ of Sight.